Recently, services which provide a place for communication through a human network based on a trust relationship between users have become increasingly popular. One such service is called Social Networking Service (hereinafter referred to as “SNS”), and various SNSs are provided by carriers. In SNS, unlike normal web sites and blogs, a range of disclosure in which information such as user's profile, diary, and photograph is disclosed can be specified. Specifically, a range of disclosure can be specified such that information is disclosed only among the user's friends, friends of the user's friend, or the like. By specifying a range of disclosure like this, communication among specific users can be established. For example, examples of this technique have been disclosed in Japanese Patent-Laid Open No. 2006-4318 and Japanese Patent-Laid Open No. 2006-72812.